JsonFileWrapper 1.1.0

JsonFileWrapper

A simple, educational generic wrapper for JSON file operations in .NET. Simplifies loading and saving strongly-typed objects to JSON files with automatic backup support.

Overview

JsonFileWrapper was created as an educational tool to demonstrate generic classes and the Bridge design pattern. It provides a clean API for persisting objects to JSON files without writing repetitive serialization code.

Features

• ✅ Generic Type Support - Works with any serializable .NET type
• ✅ Automatic Backup - Creates .bak files before overwriting
• ✅ Zero External Dependencies - Uses built-in System.Text.Json
• ✅ Simple API - Load, modify, and save in just a few lines
• ✅ Null-Safe - Handles missing files and null data gracefully
• ✅ IDisposable Support - Auto-saves on disposal

Requirements

• .NET 8.0 or higher

Installation

Package Manager Console

Install-Package JsonFileWrapper

.NET CLI

dotnet add package JsonFileWrapper

Package Reference

<PackageReference Include="JsonFileWrapper" Version="1.1.0" />

Quick Start

Define Your Model

public class Person
{
    public string Name { get; set; } = string.Empty;
    public string LastName { get; set; } = string.Empty;
    public int Age { get; set; }
    public string Movie { get; set; } = string.Empty; // Film de medverkat i
    public int Year { get; set; } // Årtal för filmen
}

Load, Modify, and Save

using MarcusMedinaPro.JsonFileWrapper;

// Create or load existing file
var file = new JsonFile<List<Person>>("actors")
{
    Data = new List<Person>()
};

// Add data
file.Data.Add(new Person { Name = "Allison", LastName = "Williams", Age = 35, Movie = "M3GAN", Year = 2022 });
file.Data.Add(new Person { Name = "Violet", LastName = "McGraw", Age = 13, Movie = "M3GAN", Year = 2022 });
file.Data.Add(new Person { Name = "Vera", LastName = "Farmiga", Age = 50, Movie = "The Conjuring", Year = 2013 });
file.Data.Add(new Person { Name = "Patrick", LastName = "Wilson", Age = 50, Movie = "The Conjuring", Year = 2013 });

// Save to actors.json
file.Save();

Output (actors.json)

[
  {
    "Name": "Allison",
    "LastName": "Williams",
    "Age": 35,
    "Movie": "M3GAN",
    "Year": 2022
  },
  {
    "Name": "Violet",
    "LastName": "McGraw",
    "Age": 13,
    "Movie": "M3GAN",
    "Year": 2022
  },
  {
    "Name": "Vera",
    "LastName": "Farmiga",
    "Age": 50,
    "Movie": "The Conjuring",
    "Year": 2013
  },
  {
    "Name": "Patrick",
    "LastName": "Wilson",
    "Age": 50,
    "Movie": "The Conjuring",
    "Year": 2013
  }
]

Advanced Usage

Custom JSON Formatting

var file = new JsonFile<List<Person>>("data")
{
    Format = new JsonSerializerOptions
    {
        WriteIndented = false,  // Compact JSON
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
    }
};

Implicit Conversion

var file = new JsonFile<List<Person>>("actors");
List<Person> people = file;  // Implicit conversion

Auto-Save with IDisposable

using (var file = new JsonFile<List<Person>>("actors"))
{
    file.Data.Add(new Person { Name = "New", LastName = "Actor" });
    // Automatically saves on dispose
}

API Reference

Constructor

public JsonFile(string filename)

Creates a new instance and attempts to load existing data from {filename}.json.

Properties

Methods

How It Works

1. Load: Reads JSON file if it exists, deserializes to type T
2. Modify: Work with the strongly-typed Data property
3. Save:
   • Creates backup (.json.bak) of existing file
   • Writes new data to .json file

Error Handling

JsonFileWrapper handles common errors gracefully:

• Missing files: Returns new instance of T
• Corrupt JSON: Logs error and returns new instance
• File access errors: Logs error using Debug.WriteLine

Educational Purpose

This library demonstrates several C# concepts:

• Generic Classes: JsonFile<T> works with any type
• Design Patterns: Loosely based on the Bridge pattern
• Serialization: Using modern System.Text.Json
• Resource Management: Implementing IDisposable

Migration from v1.0.x

Version 1.1.0 introduces breaking changes:

• Newtonsoft.Json → System.Text.Json: Update your Format settings
• .NET 6 → .NET 8: Update project target framework
• MSTest → xUnit: If using tests, update test framework

Updating JsonSerializerSettings

Before (v1.0.x with Newtonsoft.Json):

Format = new JsonSerializerSettings
{
    Formatting = Formatting.Indented,
    NullValueHandling = NullValueHandling.Ignore
};

After (v1.1.0 with System.Text.Json):

Format = new JsonSerializerOptions
{
    WriteIndented = true,
    DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
};

Contributing

Contributions are welcome! Please:

1. Open an issue to discuss major changes
2. Fork the repository
3. Create a feature branch
4. Add/update tests as appropriate
5. Submit a pull request

Source Code

Full source available on GitHub

License

Licensed under MIT License

Credits

• Author: Marcus Medina
• Icon: Json file Icon by First Styles on Iconscout

Made with ❤️ for educational purposes